Hammer-drill.



PATENTED APR. 24

No. l818,6.'58.

W. PRELLWITZ. HAMMER DRILL.

APPLICATION FILED DBO. 7.1905

Y 4//4 ft),

enr-ran -srnfrns WILLIAM PRELLWITZ, OF PHILLIPSBURG, N Er JERSEY,

Parana Assieme 'ro INGERSOLL-RAND COMPANY, OF NEr YORK, N. Y., A COHlOltA'llON OF NEW JERSEY.

HAMMER-DRILL..

Specification of Letters Patent.

' genna pin 24, 1906.

Application tiled December 7,1905. Serial No. 290.690.

To /tZZ whom it may concern.-

Be it known that VILLIAH PRELLwiTz, a citizen of the United States, andA a resident of Phillipsburg, in the county of Warren and State of New Jersey, have invented a new and useful Improvement in Hammer-Drills,

of which the following is a specification.

My invention relates to lia1nmerdrills, and

articularly to a hammer-drill having an airciently to revent the ready forward feed of the tool-cy inder within the casing, owing to the pressure of air back of the same, and, in fact, the casing is frequently 4so much distorted as to absolutely prevent the forward feed of the said hammer-cylinder.

The objects of my invention are to provide certain improvements in the construction, form, and arran ement of the several parts whereby the wa ls of the protective casing are entirely s aced from the tool-cylinder, the tool-cylin( er being supported from the* ends of the casing and the entire space within the Casin(r bein(y opened to the air-feed, the forward feed of the toolcylinder being insured by the excess of pressure back of the same, owing to the fact that the tail-rod of the cylinder is of less diameter than the cylinder itself. This arrangement revents all danger of the tool-cylinder stic 'ing in the protective casing, and thereby interfering with its forward feed.

A further object is to provide a structure of the above character in which the exhaust from the piston-chamber is led through the cylinder to a point exterior to the protective casing and through the tail-rod to a point exterior to the casing.

In the accompanying drawings, Figure 1 is a view of the hammer-drill in side elevation, a portion of the protective casing being broken away to more clearly show the position of the tool-cylinder.therein; and Fig. 2 is a longitudinal central section through the drill.

.rotate the drill.

The tool-cylinder is denoted by 1. To this cylinder is screwed a head-block 2, in whicn is located the usual valve-box 3 of any wellknown or approved form, the holes 4 being formed in the head-block 2 for the admission of air to the valve-box. The contracted portion of the cylinder is provided with the usual hammer-piston chamber 5, in which the hamnier-piston 6 is fitted to reciprocate.

The drill-tool is denoted by 7, and it is held in the usual bushing S at the forward end of the cylinder 1 in position to be struck by the haninierupiston 6.

A hollow tail-rod 9 extends rearwardly from the head-block l of the tool-cylinder 1, which tail-rod is provided at its rear end with the usual operating-handle 1.0, arranged to A hollow protective casing has its cylindrical Walls 11 entirely spaced from the cylinder 1, which casinfr is provided at its ends 12 and 13 with packed bearings 14 15, the tail-rod 9 being supported by and tted to slide in the bearing 14 at the end 12 of the casing and the cylinder being supported by and fitted to slide in the bearing 15 at the end 13 of the casing.

An air-supply inlet 16 is located in the rear end 12 of the rotective casing in position to permit a supp y of the motive fluid to enter the interior of the casing and to ass through the walls 4 into position to bc irected from the valve-box 3 to the front or back of the hammer-piston 6 in the usual manner.

An exhaust-port 17 leads from the chamber 5 in front of the hammer-piston 6 through the side walls of the cylinder 1 to a point exterior to the casing. ln the present instance the exhaust-port 17 opens through the end of the said cylinder at one side of the bushing S,

The exhaust-port 1S for the chamber 5 in back ofthe hammer-,piston leads through the tail-rod 9 to a point exterior to the protective casing-in the resent instance through an annular series of iioles 19 adjacent to the handle 10 at the rear end of the tail-rod. T o direct the exhaust away from the operator from this last-named exhaust-port, I providers deflector 20, which surrounds the annular series of holes 19, which dellector in the present instance is shown as forming an integral part of the handle 10. y

By the construction herein shown and dcscribed it will be seen that the protective cas- IOO out interfering with the forward feed of' the cylinder7 for the reason that any slight distortion in the casing will not'afect the cylin-` der, as it is entirely supported by the ends oi the casing.

What If claim is- 1. In a hammer-drill, a hammer-cylinder and a hollow protective casing therefor having its walls entirely spaced Aiiorn the cylinder, the cylinder being supported only by the ends of the casing for the purpose set forth.

2. In aliamrner-drill, a hammer-cylinder, its tail-rod and a protective casing having its Walls entirely spacedfrom the cylinder, the cylinder and tail-rodv having sliding engagements with and supported only by the ends of the casing for the dpurpose set forth.

3.` In a hainrnerrill, a hammer-cylinder,

' its tail-rod of less diameter than the cylinder i cylinder, the cylinder having one exhaust- 'port leading therethrough to a point exterior to the casing and another exhaust-port leading through the tail-rod to a point exterior to the casing. I v6.` In a hammer-drill, a hammer-cylinder,

its tail-rod, a protective casing for the cylinder,' the cylinder having an exhaust-port leading through the tail-rod'to a point exte- Y Arior to the casing and a deiiector on the tail 4rod for directing the exhaust away from the operator.

7. In a hammer-drill, a hammer-cylinder, its tail-rod, a protective casing'for the cylinder, the cylinder having one exhaust-port leading therethrough to a point exterior to the cajsin and another exhaust-port leading through t e tail-rod to a point exterior to the erases casing and a deilector on the tail-rod for directing the exhaust from the last-named exhaust-port away from the operator.

8. In a hammer-drill, a hammer-cylinder, its tail-rod and a protective casin having its y'Walls entirely spaced from the cy inder, said cylinder having an exhaust port leading through its side Walls to a point exterior to the casing.

9. In a hammer-drill, a hammer-cylinder, its tail-rod and a protective casin having its walls entirely spaced from the cy inder7 said cylinder having an exhaust port leading through the tail-rod to a point exterior to the casing. 4

1G. In a hammer-drill, a hammer-cylinder, its tail-rod and a protective casin having its walls entirely spacedv from the cy inder, said cylinder having one exhaust-port leading therethrough to a point exterior to the casin and another exhaust-port leading throng the tail-rod to a point exterior to the casing.

l1. In a hammer-drill, a hammer-cylinder, its 'tail-rod, a protective casing having its Walls entirely spaced from the cylinder, said cylinder having an exhaust port leading through its tail-rod to a point exterior to the casing and a deilector on the tail-rod arranged to direct the exhaust away from the y operator.

12. In a hammer-drill, a hammer-cylinder,

its tail-rod,' a protective-casing having yits walls entirely spaced from the cylinder, said cylinder having one exhansh'port-leading therethrough to a point exterior to thecasing and another exhaust-port leading through the tail-rod to a point exterior to the casing and a deector on the tail-rod for directing the exhaust from the last-named port' away from the operator. Y

In testimony that I clairn'the'foregoing as my invention I have signed rny name, in presence of two Witnesses, this 5th day of December, i905.

Gao. J. HARTMANN, IPI/D. MAXWELL. 

